1. Field of the Invention
The present invention relates to the field of packaging technology, and in particular to an OLED (Organic Light-Emitting Diode) package structure and a packaging method.
2. The Related Arts
OLED stands for organic light emitting diode, which has various advantages, such as being self-luminous, high brightness, wide view angle, high contrast, being flexible, and low power consumption and is considered the new generation of display measures that gradually takes the place of the conventional liquid crystal displays by being widely used in mobile phone screens, computer displays, and full-color televisions. The OLED displaying technology is different from the liquid crystal displaying technology in that no backlighting is needed and an extremely thin coating layer of an organic material and a glass substrate are used in such a way that when an electrical current flows therethrough, the organic material emits light. However, since the organic material is highly reactive to moisture and oxygen, an OLED display, which is a display device based on such an organic material, must require extremely high standard of packaging.
Most of the organic substances contained in an OLED light emission layer are extremely sensitive to pollutions, oxygen, and moisture contained in the atmosphere. Electrochemical corrosion may readily occur in a humid environment so as to severely affect the lifespan of an OLED device. Interior sealability of an OLED device must be improved by means of device packaging in order to achieve isolation from the outside environment as better as possible. This is of vital importance to the stability of light emission of an OLED device.
Packaging of an OLED device is generally achieved with a frit based laser packaging process as illustrated in FIG. 1. Such a packaging process is carried out by forming a loop of fritted glass 300 around a circumference of a package lid 200, which is then positioned on a substrate 100 on which an OLED device 400 to be packaged is arranged. A laser is then applied to instantaneously heat the fritted glass 300 to melt thereby adhering the two glass sheets together. Frit based laser technology involves an inorganic packaging medium so as to exhibits a strong capability of blocking moisture and oxygen and a device so obtained has an extended lifespan, making it particularly suitable for the OLED technology that is generally sensitive to moisture and oxygen. However, the frit based laser packaging process generally needs the gap of a cavity to be large, making it impossible to provide a sufficient mechanical strength and thus not suitable for OLED display panels of large sizes. Further, thermal radiation occurs when the fritted glass is being molten and this may cause burning of a light emission element.
Thus, it is desired to provide a novel OLED package structure and a packaging method that overcome the above problems.